http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/126 Annual Research sessions held in the year 2015 2026-04-09T04:39:03Z http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/350 Annual Research Session-2015 2015-11-16T00:00:00Z http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/347 An Implication of Agent-based Simulation Model for Land Tenure Security and Utility Dynamics Piyasena, N.M.P.M; Eckardt, F As UN-HABITAT highlighted urban squatting is one of the major issues that facing by the developing countries. It is well known fact that tenure insecurity that results from urban squatting hiders the economic progress of a country. It has predicted that the issue of tenure insecurity become severe in coming decades. Urban squatting mainly results from human-spatial relations govern by the market forces. However, expansion of squatting cannot only be deducted to market forces, other socio-economic relations associated with urban spaces such as inadequate land policies, mismanagement of public lands and attitudes of people are also contributing to this end. This makes urban squatting is a difficult issue to handle. Econometric models, however, the above human relations have largely neglected and hence they lead for ineffective decision making. Lack of understanding of the impacts of policy implication is another issue that face by the policy makers. Therefore, understanding the total-element relations and their dynamics within the context of urban land tenure is imperative for effective policy implication. In the current study, a literature review has been conducted to identify the socio-economic factors that are affecting on the expected benefits from land resources. This has led to identify the major elements of land tenure security that can be influenced by the human-spatial relations. Perceived uncertainty associated with expected benefits from those elements, however, is determined through interaction of three worlds, namely, world of social structure, world of perceptual structures and world of cognitive structures, and are codetermined within large autopietic system. Self-congruity theories, social structural theories, as well as cognitive science theories were use to define an analytical framework for the above interactions. This framework and the econometric model on utility of land tenure were then utilized to define an agent-based simulation model for land tenure security-utility dynamic model. The outcome of the model shows that total-element relations, sociometric, econometric, and cognitive structures of agents are imperative for successful policy implication. 2015-11-16T00:00:00Z http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/346 Efficient Generation of 3D Building Models from Airborne Laser Scanning Point Clouds and Aerial Photos Perera, G.S.N; Maas, H.G Geometrically and topologically correct 3D building models are required to satisfy the increasing demand in, for instance 3D cadaster, virtual reality, emergency response, robot navigation, and urban planning. Airborne Laser Scanning (ALS) is still the preferred data acquisition system for automated building modeling. Although ALS point clouds are useful for a highly automated processing workflow with high vertical accuracy, their sparse point distribution reduces the planimetric accuracy of model boundaries significantly. In comparison to the ground sampling of digital aerial images to the centimeter level, the planimetric accuracy of building models derived from point clouds is severely limited. Since point clouds and images have rather complementary properties, the integration of these two data sources leads to building models of high vertical accuracy, as well as planimetrical accuracy. In this study, a new framework for the automatic reconstruction of building models by integrating ALS point clouds and digital aerial image data is proposed. Topology preserving 3D roof models is first derived from point clouds. These models are subsequently refined to increase the planimentric accuracy with image data. In addition, some of the topological inaccuracies of the initial roof models are rectified. A novel approach employing a cycle graph analysis is introduced to generate the topology preserving roof models from point clouds. Initial and refined roof models derived from the developed schemes are analyzed with the ISPRS benchmark test data. The results of the three test scenes showed that both methods are acceptable, and can be used with more complex urban scenes. While proving the robustness of the cycle graph approach by the initial results, the refined models demonstrate that image integration improves the planimentric accuracy significantly, with almost 100% topological and geometrical correctness. 2015-11-16T00:00:00Z http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/344 Heterogeneous Sorption of Heavy Metal Cadmium by a Waste Material from Aquaculture Ponds: A Duality Approach Malavipathirana, S; Wimalasir, S; Priyantha, N; Kulasooriya, T.P.K Attention of the researchers, at present, is deserved by the heavy metal burden on the mankind and the environment. The issue is specially triggered with continuous anthropogenic inputs of chemical substances supposed to be rich in heavy metals. In particular, heavy metals such as cadmium (Cd) and arsenic (As) are considered as one of the causes of the Chronic Kidney Diseases of uncertain etiology (CKDu) in Sri Lanka. Consequently, management of such heavy metal inputs to the environment and also amputation of them are accounting priority area of research. Naturally forming aquaculture pond waste material (aqua waste) has demonstrated promising adsorption characteristics adding a value to the waste and reducing the burden of Cd in aqueous phase at ambient conditions simultaneously. This duality approach showed that under the optimized conditions of as little contact time and settling time as 30 minutes, unmodified aqua waste showed 98% removal of Cd from 10 mg dm-3 aqueous solution at 1:20 adsorbent/solution ratio. Amongst different adsorption isotherm models, the Freundlich model in its linear form depicted validity of the adsorbent- adsorbate (Cd) adsorption system at equilibrium with a high regression coefficient of 0.933. Such an adsorption is characterized by non-ideal sorption on heterogeneous surfaces, which explains multilayer sorption. Thus, the aqua waste exhibits its potential towards real time applications as an adsorbent for heavy metal Cd from aqueous solutions without prior modification of the material 2015-11-16T00:00:00Z